FIX Client Simulator User Guide
Product Overview
EPAM B2BITS FIX Client Simulator (FCS) is a rich desktop UI application. It allows to simulate multiple FIX protocol-defined buy-side- and sell-side-oriented workflows and create repeatable test scenarios for FIX sessions. FCS combines the ability to generate, manually enter, and edit FIX messages in row format and via pre-defined forms. It allows to assemble and replay FIX messages in a highly automated fashion with automatic handling of sequence numbers and identities.
FCS is used in the following use cases:
- OMS/EMS functional and stress testing
- Automated FIX integration testing
- FIX protocol implementations
- Errors reproducing
FCS covers all spectrum of FIX protocol versions and supports custom extensions and QuickFIX-formatted dictionaries.
FIX Client Simulator features
- Establishing multiple acceptor and/or initiator sessions on local and/or remote hosts
- Support of unregistered acceptor sessions
- Restarting the working session with or without session logs restoration
- Restoring session state and configurations on FCS startup
- Support of all FIX message types (pre-trade, trade, post-trade, market data, etc.)
- Standard 4.0 - FIXLatest FIX application versions support
- Custom dictionaries support
- Overriding SenderCompID and TargetCompID for the established session
- Manual sequence numbers definition or reset
- Validation of incoming and outgoing FIX and QuickFIX messages
- Wide range of FIX session settings including Custom Logon message
- Replaying selected log files
- Ability to load, modify, and send a file containing a preset message or batch of messages
- Enabling/disabling message re-sending
- Sending messages in a defined interval
- Tag values autoincrement
- Events monitoring:
- sent and received messages
- session states
- Creating, recording, editing, and running test scenarios for FIX sessions
Prerequisites and System Requirements
FIX Client Simulator is based on FIX Antenna C/C++/.NET FIX Engine. It can be installed separately or as a part of the FIX Antenna .NET package.
- Any modern Intel-based server or workstation with a 64-bit CPU can be used as hardware.
- Supported operating systems:
- Windows 7
- Windows 8
- Windows 10
- Windows 11
- Windows Server 2008 R2
- Windows Server 2012
- Windows Server 2016
- Ubuntu Linux 20.04
- Ubuntu Linux 22.04
- Rocky Linux 8
- VS 2010 C++ Redistributable Package (x64) should be installed before the FIX Client Simulator's installation.
Installation on Linux Mint and Ubuntu
FCS has been available on Linux since the FIX Client Simulator 3.5.0 release.
To install FIX Client Simulator on Linux Mint and Ubuntu follow the instructions below:
- Install Wine (instruction for Ubuntu and Mint).
Install Winetricks using the following commands:
sudo apt install winetricks
Install .NET Framework 4.8 using the following commands:
winetricks --force dotnet48 winetricks --force corefonts
If Wine prompts for installing Mono, click Cancel. Please refer to the HowTo section for more details.
Navigate to the FCS folder and run it.
cd ./FCS_<version> wine Fcs.exe
Installation on macOS
FCS has been available on macOS since the FIX Client Simulator 3.5.0 release.
To install FIX Client Simulator on macOS follow the instructions below:
- Install Wine
Option 1 - Download and install Wine from the official site
Option 2 - Download and install Wine using Brew
brew install --cask wine-stable
Navigate to the FCS folder and run it.
Option 1 - via Terminal
cd ./FCS_<version> wine Fcs.exe
- Option 2 - via context menu
Configuration
FIX Client Simulator can be configured in the Fcs.exe.config file via the following properties:
Property Name | Description | Required | Default Value |
---|---|---|---|
DaysToKeepEventViewLog | This property is available since the FIX Client Simulator 3.3.0 version. This property defines the number of days for which the session logs will be restored during the logs restoration process. Possible values: int | N | 0 |
MainWindowTitle | This property is available since the FIX Client Simulator 3.6.0 version. This property defines the name of the main FCS application window. If not defined then the default 'EPAM® FIX Client Simulator' title will be displayed. Possible values: string | N | null |
StoreSettingsInUserFolder | This property is available since the FIX Client Simulator 3.2.0 version. This property defines whether the user.config file will be stored in the current user directory. Possible values: true | false | N | false |
TestScenarioFolder | This property is available since the FIX Client Simulator 3.7.0 version. This property defines the path to the system directory where created Test Scenarios will be stored. When the TestScenarioFolder property is defined with the default 'null' value all created Test Scenarios must be stored in the default TestScenarios folder within the application package. Possible values: string | N | null |
FIX Session creation
To create a session, choose: Session → Create new FIX session...:
Specify the session type (Initiator or Acceptor) and parameters (SenderCompID, TargetCompID, remote host, and port) in the Create Session window:
The left column of the Create Session window includes all required parameters. If at least one of them is specified incorrectly, the session will not be created.
The right column includes extended parameters that are optional.
Custom Logon messages can be used after ticking the corresponding line at the bottom of the window.
After the session is established you will see it in the Session List section. All received messages will be displayed in the Events Viewer section below.
Kafka Session creation
To create a session, choose: Session → Create new Kafka Session...:
Specify the session type (Producer or Consumer) and parameters (remote host, remote port, topic, key, authentication (None/SASL), SSL if needed, and Click - OK button in the Create Kafka Session window:
After the Kafka session is created you will see it in the Session List section. All sent or received messages will be displayed in the Events Viewer section below.
The "Backup Connection Parameters" section
The FIX Client Simulator 3.10.0 release introduces the "Backup Connection Parameters" section, which allows configuring a backup connection to ensure a seamless transition if the primary connection fails.
- Enable Cyclic Switch Backup Connection will cyclically try to reconnect to the primary and backup if either is lost
- Enable Auto Switch to Backup Connection automatically switches to the backup if the primary fails after a few attempts. If disabled, no backup attempt will be made
- Keep Connection State retains the same log files for both connections if enabled. If disabled, separate logs will be created for the backup connection
Multiline session display
The FIX Client Simulator 3.9.0 update allows to view sessions with multiple lines within the Session list. This view can be accessed by following these steps:
- Go to the Options menu
- Select the Multiple session information
After enabling "Multiple session information" in the Options menu, the details for each session in the list will now be displayed across multiple lines.
This provides a clearer view of all the information for each session
Manual sequence numbers definition and reset
To define sequence numbers manually, open the Create Session window and specify values in InSeqNum and OutSeqNum input fields:
To reset sequence numbers manually open the Create Session window and tick Reset Sequence number.
Display administrative messages in the console
To see or hide administrative messages in the console open the Create Session window and select the Show session messages checkbox.
You can select a session and select the Show session messages option in the Session menu or in the context menu of the session window.
This setting is stored as other session settings and restored after the session restart.
Sending messages
In order to send a message, please specify the message in the Send Message tab, choose a session, and press the Send button. You can send any text you need, including arbitrary content such as JSON (used for Kafka messages). Please note that the sequence number and sending time will be set automatically.
To override SenderCompID and TargetCompID select the Override SenderCompIDs or Override TargetCompID option in the main application menu in the Options section.
To specify the message-sending rate enter the value in the Rate input field on the Send Message tab.
Message re-sending
To enable message re-sending open Options from the context menu and select the Allow message re-sending option.
Sending selected messages
This feature is available since the FIX Client Simulator 3.0.0 release.
In order to send the message(s), please open the Send Message tab, choose a session, and type the message(s) in the text box. To send all messages specified in Send Message tab, press the Send all button.
To send only selected message(s) select it in the Send Message tab and press Send Selected button. Only message(s) starting with the 8 tag and ending with the 10 tag will be sent.
The sent message will be highlighted in light grey.
To send messages one by one select the message in the Send Message tab and press the Send Current and go Next button. The first sent message will be highlighted in light grey and the next message will be highlighted in dark grey.
To reset the selection of messages, please press the Reset button.
Autoincrement tag values
The feature works with a FIX or Kafka session
The ability to set the value starting from which the value of the tag will be autoincremented is available since FIX Client Simulator 3.1.0 release.
When sending messages, the values of the specified numeric tags can be automatically increased with each sending. Tag numbers that must be changed are set in the Autoincrement tags field.
If you want to change the values of several tags, the tag numbers must be separated by a space, e.g. '11 38'.
If the tag is included in the Repeating group, the root tag must go first then the '\' symbol, and then the particular tag number, e.g. '453/448'.
If you want to set the value starting from which the value of the tag must be autoincremented, the tag and its value must be separated by the '=' symbol, e.g. '11 = 100' or '58 = "Hello 22"' - for value with the space or '58="Hello \" 22"' - for value with the space and " symbol.
Starting from FIX Client Simulator 3.2.0 release autoincrementation can be reset only by changing the value in the Autoincrement tags field.
Replay log
The feature works with a FIX or Kafka session
The ability to replay QuickFIX-formatted log files is available since FIX Client Simulator 3.1.0 release.
To send messages from the log file to the session (replay log file), please specify the log file in the Replay tab, choose a session, and press the Play button.
Log files of the following formats may be replayed:
- *.in
- *.out
- *.fix
- *.msg
- *.body
Also provides the ability:
- to suspend sending messages from the log (Pause button)
- to stop sending messages from the log (Stop button)
- to send messages one by one (just after Loading file, after Pause, after Stop. Next button)
Please note that the Replay function does not send Administrative messages (35=0, 35=A, 35=5, 35=3, 35=2, 35=4, and 35=2) by design.
To send a specific range of messages it is possible to specify a filter by Sequence numbers or/and types of messages (Filter).
The log can be replayed several times. The number of replays is set by the Send count parameter.
The Send count parameter is ignored if messages are sent one by one
To specify the message-sending rate for message sending enter the value in the Rate field in the Replay tab. Also, the interval can be calculated based on the timestamp in the log file (Use the timestamps tick).
In addition, the interval for sending messages is changed by setting a multiplier other than one (Speed parameter).
Events monitoring
The upper right part of the FIX Client Simulator window displays the message(s) to be sent.
The upper left part shows the list of active sessions.
The lower part is the Events Viewer section, where each record corresponds to one event and consists of the event time, name, and description.
The New Events Viewer interface described below is available since the FIX Client Simulator 2.28.0 release.
Events Viewer displays events and messages of the chosen session in the Session List section. If you choose several sessions, all events belonging to the sessions are displayed in the Events Viewer section.
Whole messages or only their parts can be copied from the Events Viewer section.
- To copy the whole message with the timestamp it must be right-clicked on and then the Copy Message action must be selected in the context menu.
- To copy the message without timestamp it must be right-clicked on and then the Smart Copy action must be selected from the context menu.
- To copy the part of the message this part must be selected/highlighted and right-clicked on and then the Copy action must be selected in the context menu.
Checkboxes on the bottom of the Event Viewer section allow you to adjust the completeness of the event display, including messages. You can show or hide timestamps, header, or trailer of a FIX message, application messages, and session messages.
Events and messages in the Events Viewer section can be filtered using the Filter text field. All special symbols are supported except '/'.
Incoming, outgoing, and console messages are highlighted with different colors for visual usability. The colors can be changed in the Fcs.exe.config file.
Detailed message view from Events Viewer
In FIX Client Simulator 3.9.0, it is possible to access detailed information about individual messages within the Event Viewer. To view these details, it is required to:
- Select the required message
- Right-click on the message
- Select the option "View FIX message"
When right-clicking a message in the Event Viewer and selecting "View FIX message" a separate "Message Details" window opens. This window displays the details of the selected message in FIX message format, providing a comprehensive view of its contents.
The Events Viewer section can be spliced into three windows (Incoming, Outgoing, and Console) by choosing the Split Window checkbox. No highlighting is applied in this mode.
It is possible to auto-scroll the events by clicking Events Viewer → Auto scroll in the main menu so that Events Viewer will display the latest events first.
To clear the Events Viewer section select the Clear event viewer option from the Events Viewer menu.
Tag order
FIX Client Simulator changes the tags' order in Event Viewer according to the dictionaries' structure.
It happens when the dictionary used by the Simple Client, has not had the same tag order as it is in the counterparty's specification. In the Event Viewer, the messages are represented according to the dictionary's structure. The original tag order may be seen in incoming log files.
If you want to keep the order the same as in the received message, the dictionary should be updated according to the counterparty's specifications.
How to change the order of tags in a FIX message?
Example showing how to re-order tags for the screenshot above
TimeInForce (tag 59) is located after block parties (tag 453)
TimeInForce (tag 59) is located before block parties (tag 453)
Searching for a raw message
Users can search for a text in a raw message using the search line below the Send Message field:
Writing messages
You can write a message in the Send Message field and edit it:
To enter a field delimiter click the right button in Send Message field and choose Insert <SOH>:
Loading predefined message or message batch
You can load a preset message and edit it before sending it.
Go to Message -> Load to load a preset message and click the Send button to send it to the counterparty. Or select Message -> Send batch to load and immediately (without editing) send a number of preset messages from one file:
Create messages from the template
You can create a template message from a dictionary with the required tags and edit it before sending it.
Go to Message -> Create to load a list of messages from a dictionary, which is corresponding to the selected session. Click the Create button to open it in the editable table for further filling of tag values and sending the message to the counterparty:
Generate messages
Execution Report
The ability to autogenerate Execution Report (35=8) for the incoming New Order Single (35=D) message is available since FIX Client Simulator 3.3.0 version.
FIX Client Simulator provides the ability to autogenerate New, Partially Filled, and Filled Execution Report (35=8) for incoming New Order Single (35=D) messages in the Events Viewer section.
The following steps must be taken:
- Select the particular incoming New Order Single (35=D) in the Events Viewer section.
- Right-click on the selected message.
- Select the Exec Report - New or Exec Report - Fill or Exec Report - Partial Fill action in the context menu.
The ability to autogenerate Execution Report (35=8) for the incoming Order Status Request (35=H) message is available since FIX Client Simulator 3.7.0 version.
Also, it is possible to autogenerate Status Execution Report (35=8) messages for incoming Order Status Request (35=H) messages in the Events Viewer section.
The following steps must be taken:
- Select the particula